fair suck of the sav there Rip, i agree there are a lot of tall blokes on minis, but 6'10'' on a mini may as well be 7'13''.....
028NVD have you considered a bike like the Orion XB31 in 19/16 configuration?
these can be found on ebay second hand for around $500-$650, and offer much better performance than a bigfoot 150, and will actually have ergonomics you will fit on... even on a big foot, being 6'10 your knees will be wrapped around your ears...
The XB-31 in 3/4bike configuration (19'' front wheel, 16'' rear wheel) has much better ergos than any pitbike, while still retaining the size and chuckability, as well as affordability of a pittie... they also have the added benefit only a 250cc vertical longstroke motor can offer, which is vast amounts more torque than most stock sub-150cc pitbike engines... They also have a longer wheelbase, without the "bunched up" geometry of a bigfoot... (17/14)
Search "pitbike" on egay, click on the sub-section at the top of the page that says "other trail bikes", you are bound to find heaps of XB-31's on there...
They are also called Atomik Pro-X 250's, depending on who the dealer was... basically you're looking for a 250cc china bike, that isnt an Atomik Blitz or Kuda pro...
Ok, so it may not be a pitty, but you'll hate it much less than a bigfoot mini...